Three-dimensional printing apparatus and method for three-dimensional printing

Abstract

A method for three-dimensional printing for forming a three-dimensional structure on a moving platform is provided. The three-dimensional structure includes a shell portion and a foamy filling portion. The method includes the following: a digital shell model of the three-dimensional structure is built. Next, the digital shell model is sliced into a plurality of cross-section information. Next, a corresponding liquid forming material is cured on the moving platform according to the cross-section information to form a plurality of shell layers. Next, foaming process is performed on the liquid forming material to form a foamy forming material. Next, the foamy forming material located within the corresponding shell layers is cured to form a plurality of foamy filling layers. Afterward, the shell layers and the foamy filling layers are alternately formed on the moving platform and stacked to form the three-dimensional structure. A three-dimensional printing apparatus adopting the method is also provided.

What is claimed is: 
     
       1. A three-dimensional printing apparatus, used to form a three-dimensional structure, the three-dimensional structure comprising a shell portion and a foamy filling portion, comprising:
 a tank filled with a liquid forming material; 
 a foaming unit disposed in the tank and adapted to make the liquid forming material generate a plurality of bubbles to form a foamy forming material; 
 a centrifuge defoaming unit disposed at the tank and adapted to remove the bubbles in the foamy forming material to return the foamy forming material to the liquid forming material; 
 a moving platform movably disposed above the tank; 
 a translating light source movably disposed on one side of the tank to respectively irradiate and cure the liquid forming material and the foamy forming material on the moving platform; and 
 a control unit coupled to the translating light source, the moving platform, the foaming unit, and the centrifuge defoaming unit to control the moving platform to be immersed in the liquid forming material and alternately drive the foaming unit and the centrifuge defoaming unit to perform foaming and defoaming processes on the liquid forming material and correspondingly control the translating light source to alternately cure the liquid forming material and the foamy forming material on the moving platform layer by layer, wherein the cured liquid forming material is stacked on the moving platform layer by layer to form the shell portion, and the cured foamy forming material is stacked on the moving platform layer by layer to form the foamy filling portion.